Thomas Sully was Philadelphia’s leading portraitist in the early nineteenth century. This work displays his characteristically fluid use of paint, a skill he learned in London in emulation of his mentor, the British Romantic portraitist Sir Thomas Lawrence. Even in an era devoted to showing children as truly childlike, Sully’s portrait of his nine-year old son, Thomas Wilcocks Sully, is unusually informal. The young Thomas is situated off-center, creating a feeling of movement and immediacy. He wears an open shirt, rumpled jacket, and straw hat. Such less restrictive costume was becoming more usual for children as it was acknowledged that play was beneficial and healthful for young people. The detail of the torn hat suggests some real, human mischief on the part of the subject that is not apparent in the rosy sweetness of his face. The viewer wonders how the hat got torn, suggesting an element of narrative rare in a portrait and tying the picture to genre painting. The tear in the hat brim also afforded Sully the opportunity to show off his ability to paint a face under a complex pattern of light and shadow. Like Copley in A Boy with a Flying Squirrel (Henry Pelham), Sully felt free to experiment in a portrait that was not a commissioned work.